The GUI buttons for inventories are currently broken.

Tracing through with a debugger, they get added to the controlList correctly, but they don't display at all.

Middle-clicking doesn't work in chests either, although it does in the main inventory.

Settings buttons do not correctly show in either.

While fixing middle-click (ab18508ddde69b6a2dddf472fa0d1ff65db96d5a) the debugger poured out some strange results for getX/YDisplayPosition. Need to check on those and see if names changed on me.

GuiContainer.width and height are apparently the whole screen, not just the inside part -- looks like I REALLY want xSize and ySize.

Go renamed variables!